This invention relates to safety apparatus for motor vehicles and, more particularly, to an apparatus for flashing a vehicle's lights to warn others of an engine stall of the vehicle.
Hazard lights have been standard equipment on motor vehicles for some time. The driver can operate these lights by pressing a switch that is usually located on the steering column. Typically, the lights are employed by a driver who has parked adjacent to a road and wishes to warn approaching drivers of the vehicle's presence. The lights may also be employed in the case of an engine stall, wherein the vehicle loses power and its rapid deceleration in a traffic lane may cause following vehicles to collide with it. However, most drivers in such an emergency are preoccupied with steering the car to safety and will not think to turn on the hazard lights.
Apparatus are known in the art for automatically turning on the hazard lights and for flashing the headlights, taillights, and parking lights as well in the case of an engine stall. U.S. Pat. No. 3,699,415, for example, discloses an apparatus having a switch activated by engine oil pressure. If the ignition is on and the pressure drops because of an engine stall, the apparatus detects the stall and flashes the warning lights while extinguishing the headlights and taillights of the vehicle. The apparatus, however, does not work well when the engine is cold. Furthermore, the loss of headlights and taillights can be a safety hazard if the vehicle is operating on a roadway at night.
U.S Pat. No. 3,882,452 discloses an improvement over the previous apparatus by monitoring the vacuum lines of the vehicle in addition to the oil pressure. The improved apparatus also causes the headlights and taillights as well as the flasher lights to flash in the event of an engine stall. Although clearly an improvement over the prior apparatus, the improved apparatus still suffers from a number of drawbacks. The vacuum and oil pressure in the engine may vary while the engine is still running, causing unintentional flashing of the lights. The constant flashing of the headlights and taillights will also quickly drain the battery of the vehicle so that it cannot be restarted without assistance.